Embodiments of the inventive concept relate to pseudo-open drain type output drivers having a de-emphasis function, semiconductor memory device including same, and related control methods.
A semiconductor memory device may be a storage device which stores data and reads the stored data as occasion arises. Semiconductor memory devices may be generally classified as Random Access Memory (RAM) and Read Only Memory (ROM).
RAM is typically a volatile memory device that loses stored data in the absence of applied power. ROM is typically a nonvolatile memory device that retains stored data even when applied power is interrupted. RAM includes dynamic RAM (DRAM), static RAM (SRAM), and the like. ROM includes programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM) including flash memory, and the like.
Semiconductor memory devices output data to external circuits using an output driver. Output drivers are usually connected to these external circuits via an output pad. Output pads are generally well understood elements that may be implemented using a variety of designs. Certain contemporary semiconductor devices incorporate a type of output driver commonly referred to as a pseudo-open drain (POD) type output driver. This type of output driver contribute to the definitions of output impedance, output signaling, etc.